GEORGETOWN, Del. -- The former pediatrician accused of abusing his companion's daughter with torture techniques took the stand Monday to explain how he cared for the girl and the difficulties she faced in her young life.

His companion, Pauline Morse; her daughter, now 12, and other prosecution witnesses have painted Morse as a father figure who delivered harsh punishment to the girl seemingly at random while favoring her younger sister, who was biologically Morse's child.

Morse countered those allegations, testifying that he cared for both girls equally. For instance, he said he made sure to give each girl the same number of Christmas gifts.

In long, winding answers to his lawyer's questions, Morse would get sidetracked at times praising his daughter's aptitude at music, running and academics.

He described the alleged victim as "a burst of sunshine" up until age 5. He said. But after an episode of sexual abuse at the hands of her teenaged stepsister discovered in 2007, Morse said, "she became defiant. She was, naturally, angry at us for not protecting her."

As she grew up, Morse said, the family went to group counseling sessions to get better at controlling her behavior and effectively using discipline.

"It pretty much was always a thrash," he said of Pauline Morse's efforts to wash the girl's hair after she turned 8 and announced she was too old for baths. He said he tried to rinse her hair under a faucet on four or five occasions.

"I did say to her, 'I'm not waterboarding you, this isn't some kind of torture. I just want your hair to be clean,'" Morse testified.

When the daughter took the stand last week to testify about her life leading up to Morse's 2012 arrest, she said Morse forced her under running water as a punishment whenever the mood struck him, and testified that the experience cut off her air supply.

She ran away from their home in July 2012 and told police she'd been abused there, which led to the arrest of both Morses. Pauline Morse pleaded guilty to some charges last year.

Morse, who lost his medical license more than 18 months ago, also told jurors he still considers himself a doctor.

"I was and am a physician," Morse said during questioning by Kevin Tray, one of his two attorneys. "I was determined and still am determined to go back to full-time practice."

Morse testified for half the day Monday and is expected to retake the stand Tuesday.